| Message ID | 20190515120942.3812-1-malat@debian.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | powerpc: silence a -Wcast-function-type warning indawr_write_file_bool | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch next (8150a153c013aa2dd1ffae43370b89ac1347a7fb) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 9 lines checked |
On Wed, May 15, 2019 at 02:09:42PM +0200, Mathieu Malaterre wrote: > In commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 > option") the following piece of code was added: > > smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0); > > Since GCC 8 this trigger the following warning about incompatible > function types: And the warning is there for a reason, and should not be hidden behind a cast. This should instead be fixed by something like this: diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index da307dd93ee3..a26b67a1be83 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -384,6 +384,12 @@ void hw_breakpoint_pmu_read(struct perf_event *bp) bool dawr_force_enable; EXPORT_SYMBOL_GPL(dawr_force_enable); + +static void set_dawr_cb(void *info) +{ + set_dawr(info); +} + static ssize_t dawr_write_file_bool(struct file *file, const char __user *user_buf, size_t count, loff_t *ppos) @@ -403,7 +409,7 @@ static ssize_t dawr_write_file_bool(struct file *file, /* If we are clearing, make sure all CPUs have the DAWR cleared */ if (!dawr_force_enable) - smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0); + smp_call_function(set_dawr_cb, &null_brk, 0); return rc; }
Hi Christoph, On Wed, May 15, 2019 at 3:14 PM Christoph Hellwig <hch@infradead.org> wrote: > > On Wed, May 15, 2019 at 02:09:42PM +0200, Mathieu Malaterre wrote: > > In commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 > > option") the following piece of code was added: > > > > smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0); > > > > Since GCC 8 this trigger the following warning about incompatible > > function types: > > And the warning is there for a reason, and should not be hidden > behind a cast. This should instead be fixed by something like this: <meme: I have no idea what I am doing> OK, thanks for the quick feedback, will send a v2 asap. > diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c > index da307dd93ee3..a26b67a1be83 100644 > --- a/arch/powerpc/kernel/hw_breakpoint.c > +++ b/arch/powerpc/kernel/hw_breakpoint.c > @@ -384,6 +384,12 @@ void hw_breakpoint_pmu_read(struct perf_event *bp) > bool dawr_force_enable; > EXPORT_SYMBOL_GPL(dawr_force_enable); > > + > +static void set_dawr_cb(void *info) > +{ > + set_dawr(info); > +} > + > static ssize_t dawr_write_file_bool(struct file *file, > const char __user *user_buf, > size_t count, loff_t *ppos) > @@ -403,7 +409,7 @@ static ssize_t dawr_write_file_bool(struct file *file, > > /* If we are clearing, make sure all CPUs have the DAWR cleared */ > if (!dawr_force_enable) > - smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0); > + smp_call_function(set_dawr_cb, &null_brk, 0); > > return rc; > }
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index f70fb89dbf60..baeb4c58de3b 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -405,7 +405,8 @@ static ssize_t dawr_write_file_bool(struct file *file, /* If we are clearing, make sure all CPUs have the DAWR cleared */ if (!dawr_force_enable) - smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0); + smp_call_function((smp_call_func_t)(void *)set_dawr, + &null_brk, 0); return rc; }
In commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option") the following piece of code was added: smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0); Since GCC 8 this trigger the following warning about incompatible function types: arch/powerpc/kernel/hw_breakpoint.c:408:21: error: cast between incompatible function types from 'int (*)(struct arch_hw_breakpoint *)' to 'void (*)(void *)' [-Werror=cast-function-type] Cast the function to an intermediate (void*) to make the compiler loose knowledge about actual type. Fixes: c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option") Cc: Michael Neuling <mikey@neuling.org> Signed-off-by: Mathieu Malaterre <malat@debian.org> --- arch/powerpc/kernel/hw_breakpoint.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)